Paravalvular Leak Protection

ABSTRACT

A prosthetic heart valve includes a collapsible and expandable stent having a proximal end and a distal end, and a collapsible and expandable valve assembly, the valve assembly including a plurality of leaflets connected to at least one of the stent and a cuff. The heart valve further includes a conformable band disposed about the perimeter of the stent near the proximal end for filling gaps between the collapsible prosthetic heart valve and a native valve annulus.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 15/467,178, filed Mar. 23, 2017, which is a continuation of U.S.patent application Ser. No. 13/797,481, filed Mar. 12, 2013, now U.S.Pat. No. 9,636,222, the disclosure of which is hereby incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The present invention relates in general to heart valve replacement and,in particular, to collapsible prosthetic heart valves. Moreparticularly, the present invention relates to devices and methods forpositioning and sealing of collapsible prosthetic heart valves.

Prosthetic heart valves that are collapsible to a relatively smallcircumferential size can be delivered into a patient less invasivelythan valves that are not collapsible. For example, a collapsible valvemay be delivered into a patient via a tube-like delivery apparatus suchas a catheter, a trocar, a laparoscopic instrument, or the like. Thiscollapsibility can avoid the need for a more invasive procedure such asfull open-chest, open-heart surgery.

Collapsible prosthetic heart valves typically take the form of a valvestructure mounted on a stent. There are two types of stents on which thevalve structures are ordinarily mounted: a self-expanding stent or aballoon-expandable stent. To place such valves into a delivery apparatusand ultimately into a patient, the valve must first be collapsed orcrimped to reduce its circumferential size.

When a collapsed prosthetic valve has reached the desired implant sitein the patient (e.g., at or near the annulus of the patient's heartvalve that is to be replaced by the prosthetic valve), the prostheticvalve can be deployed or released from the delivery apparatus andre-expanded to full operating size. For balloon-expandable valves, thisgenerally involves releasing the entire valve, and then expanding aballoon positioned within the valve stent. For self-expanding valves, onthe other hand, the stent automatically expands as the sheath coveringthe valve is withdrawn.

SUMMARY OF THE INVENTION

In some embodiments, a prosthetic heart valve includes a collapsible andexpandable stent having a proximal end and a distal end, a cuff coupledto the stent, a valve assembly including a plurality of leaflets coupledto at least one of the stent or the cuff and a conformable band havingan inner surface disposed near the perimeter of the stent adjacent theplurality of leaflets and an outer surface adapted for contacting bodytissue, the conformable band being configured to seal the valve assemblyagainst leakage by filling gaps between the prosthetic heart valve andthe body tissue.

In some embodiments, a method of sealing a prosthetic heart valve in apatient includes positioning the prosthetic heart valve within bodytissue, the prosthetic heart valve comprising (i) a collapsible andexpandable stent, (ii) a valve assembly including a plurality ofleaflets coupled to the stent and (iii) a conformable band having aninner surface disposed about the plurality of leaflets and an outersurface adapted for contacting body tissue, and expanding the stentuntil the conformable band is in sealing contact with the body tissue.In some embodiments, a prosthetic heart valve includes a collapsible andexpandable stent having a proximal end and a distal end, a valveassembly including a plurality of leaflets coupled to the stent, and aconformable band disposed about the stent between the proximal anddistal ends thereof, the band adapted for creating a fluid seal aboutthe circumference of the stent with an adjacent body tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present invention are described herein withreference to the drawings, wherein:

FIG. 1 is a side elevational view of a conventional prosthetic heartvalve including a stent;

FIG. 2 is a cross-sectional schematic illustration of the prostheticheart valve of FIG. 1 disposed within native valve annulus;

FIG. 3A illustrates one example of a conformable band in the shape of atoroid in accordance with one embodiment of the present invention;

FIG. 3B illustrates another example of a conformable band in accordancewith one embodiment of the present invention;

FIG. 3C illustrates another example of a conformable band in accordancewith one embodiment of the present invention;

FIG. 4 is a side elevational view of a conventional prosthetic heartvalve including a stent having a conformable band as shown in FIG. 3A;

FIG. 5A is a cross-sectional schematic illustration of a prostheticheart valve having a conformable band in its fully expanded state;

FIG. 5B is a cross-sectional schematic illustration of the prostheticheart valve having a conformable band of FIG. 4 disposed within nativevalve annulus;

FIG. 6 is a schematic illustration of a conformable band as shown inFIG. 3A incorporated into a heart valve;

FIG. 7A is a schematic of a prosthetic heart valve having twoconformable bands as shown in FIG. 3A arranged in different longitudinalpositions near the annulus section of a heart valve in accordance withanother embodiment of the present invention;

FIG. 7B is a schematic of an illustration of a conformable bandconfigured as a beaded chain in accordance with another embodiment ofthe present invention;

FIG. 7C is a photograph of the beaded chain of FIG. 7B disposed near theannulus section of a heart valve; and

FIGS. 8A-D illustrate the use of conformable band and the process ofsealing a heart valve within a native valve annulus.

Various embodiments of the present invention will now be described withreference to the appended drawings. It is appreciated that thesedrawings depict only some embodiments of the invention and are thereforenot to be considered limiting of its scope.

DETAILED DESCRIPTION OF THE INVENTION

Despite the various improvements that have been made to the collapsibleprosthetic heart valve delivery process, conventional devices sufferfrom some shortcomings. For example, with conventional self-expandingvalves, clinical success of the valve is dependent on accuratedeployment and anchoring. Inaccurate deployment and anchoring of thevalve increases risks such as valve migration, which may result insevere complications due to obstruction of the left ventricular outflowtract. Additionally, calcification of the aortic valve may affectperformance and the interaction between the implanted valve and thecalcified tissue is believed to be relevant to leakage as will beoutlined below.

Moreover, anatomical variations between patients may require removal ofa fully deployed heart valve from the patient if it appears that thevalve is not functioning properly. Removing a fully deployed heart valveincreases the length of the procedure and increases the risk ofinfection and/or damage to heart tissue. Thus, methods and devices aredesirable that would reduce the likelihood of removal. Methods anddevices are also desirable that would reduce the likelihood of valveleakage due to gaps formed between the implanted heart valve and patienttissue known as paravalvular leaks.

There therefore is a need for further improvements to the devices,systems, and methods for transcatheter delivery and positioning ofcollapsible prosthetic heart valves. Specifically, there is a need forfurther improvements to the devices, systems, and methods for accuratelyimplanting a prosthetic heart valve. Among other advantages, the presentinvention may address one or more of these needs.

As used herein, the term “proximal,” when used in connection with aprosthetic heart valve, refers to the end of the heart valve closest tothe heart when the heart valve is implanted in a patient, whereas theterm “distal,” when used in connection with a prosthetic heart valve,refers to the end of the heart valve farthest from the heart when theheart valve is implanted in a patient. When used in connection withdevices for delivering a prosthetic heart valve into a patient, theterms “trailing” and “leading” are to be taken as relative to the userof the delivery devices. “Trailing” is to be understood as relativelyclose to the user, and “leading” is to be understood as relativelyfarther away from the user.

FIG. 1 shows a known collapsible stent-supported prosthetic heart valve100 for use in accordance with the various embodiments of the presentdisclosure. The prosthetic heart valve 100 is designed to replace thefunction of a native aortic valve of a patient.

The prosthetic heart valve will be discussed in more detail withreference to FIG. 1. It will also be noted that while the inventionsherein described are predominately discussed in terms of a tricuspidvalve and a stent having a shape as illustrated in FIG. 1, the valvecould be a bicuspid valve, such as the mitral valve, and the stent couldhave different shapes, such as a flared or conical annulus section, aless-bulbous aortic section, and the like, and a differently shapedtransition section.

Prosthetic heart valve 100 includes an expandable stent 102 which may beformed from materials that are capable of self-expansion. Stent 102extends from a proximal or annulus end 130 to a distal or aortic end132, and includes an annulus section 140 adjacent the proximal end andan aortic section 142 adjacent the distal end. The annulus section 140has a relatively small cross-section in the expanded condition, whilethe aortic section 142 has a relatively large cross-section in theexpanded condition. Preferably, annulus section 140 is in the form of acylinder having a substantially constant diameter along its length. Atransition section 141 may taper outwardly from the annulus section 140to the aortic section 142. Each of the sections of the stent 102includes a plurality of cells 112 connected to one another in one ormore annular rows around the stent. For example, as shown in FIG. 1, theannulus section 140 may have two annular rows of complete cells 112 andthe aortic section 142 and transition section 141 may each have one ormore annular rows of partial cells 112. The cells 112 in the aorticsection 142 may be larger than the cells 112 in the annulus section 140.The larger cells in the aortic section 142 better enable the prostheticvalve 100 to be positioned without the stent structure interfering withblood flow to the coronary arteries.

Stent 102 may include one or more retaining elements 118 at the distalend 132 thereof, the retaining elements being sized and shaped tocooperate with female retaining structures (not shown) provided on thedeployment device. The engagement of retaining elements 118 with thefemale retaining structures on the deployment device helps maintainprosthetic heart valve 100 in assembled relationship with the deploymentdevice, minimizes longitudinal movement of the prosthetic heart valverelative to the deployment device during unsheathing or resheathingprocedures, and helps prevent rotation of the prosthetic heart valverelative to the deployment device as the deployment device is advancedto the target location and during deployment.

The stent 102 may also include a plurality of commissure points 116 forattaching the commissure between two adjacent leaflets to the stent. Ascan be seen in FIG. 1, the commissure points 116 may lie at theintersection of four cells 112, two of the cells being adjacent oneanother in the same annular row, and the other two cells being indifferent annular rows and lying in end-to-end relationship. Preferably,commissure points 116 are positioned entirely within annulus section 140or at the juncture of annulus section 140 and transition section 141.Commissure points 116 may include one or more eyelets which facilitatethe suturing of the leaflet commissure to the stent.

The prosthetic heart valve 100 includes a valve assembly 105 positionedin the annulus section 140. Valve assembly 105 may be secured to stent102 in the various manners described above. Valve assembly 105 includesa cuff 106 and a plurality of leaflets 108 which collectively functionas a one-way valve by contacting one another. FIG. 1 illustrates aprosthetic heart valve for replacing a native tricuspid valve, such asthe aortic valve. Accordingly, prosthetic heart valve 100 is shown inFIG. 1 with three leaflets 108, as well as three commissure points 116.However, it will be appreciated that the prosthetic heart valvesaccording to this aspect of the invention may have a greater or lessernumber of leaflets and commissure points.

Although cuff 106 is shown in FIG. 1 as being disposed on the lumenal orinner surface of annulus section 140, it is contemplated that the cuffmay be disposed on the ablumenal or outer surface of annulus section140, or may cover all or part of either or both of the lumenal andablumenal surfaces of annulus section 140. Both the cuff 106 and theleaflets 108 may be wholly or partly formed of any suitable biologicalmaterial or polymer, including those, such as PTFE, described above inconnection with prosthetic heart valve 100.

As is shown in FIG. 1, in one example the entirety of valve assembly105, including the leaflet commissures, is positioned in the annulussection 140 of stent 102. When opened, the leaflets may extend furtherinto the transition region or may be designed such that they remainsubstantially completely within the annulus region. That is,substantially the entirety of valve assembly 105 is positioned betweenthe proximal end 130 of stent 102 and the commissure points 116, andnone of the valve assembly 105 is positioned between commissure points116 and the distal end 132 of the stent.

In operation, the embodiments of the prosthetic heart valve describedabove may be used to replace a native heart valve, such as the aorticvalve, a surgical heart valve or a heart valve that has undergone asurgical procedure. The prosthetic heart valve may be delivered to thedesired site (e.g., near a native aortic annulus) using any suitabledelivery device, including the delivery devices described in detailbelow. During delivery, the prosthetic heart valve is disposed insidethe delivery device in the collapsed condition. The delivery device maybe introduced into a patient using a transfemoral, transapical ortransseptal approach. Once the delivery device has reached the targetsite, the user may deploy any of the prosthetic heart valves describedabove. Upon deployment, the prosthetic heart valve expands into secureengagement within the native aortic annulus. When the prosthetic heartvalve is properly positioned inside the heart, it works as a one-wayvalve, allowing blood to flow in one direction and preventing blood fromflowing in the opposite direction.

Problems may be encountered when implanting the prosthetic heart valve.For example, in certain procedures, collapsible valves may be implantedin a native valve annulus without first resecting the native valveleaflets. The collapsible valves may have critical clinical issuesbecause of the nature of the stenotic leaflets that are left in place.Additionally, patients with uneven calcification, bi-cuspid aortic valvedisease, and/or valve insufficiency could not be treated well, if atall, with the current collapsible valve designs.

The reliance on unevenly calcified leaflets for proper valve placementand seating could lead to several problems, such as paravalvular leakage(PV leak), which can have severely adverse clinical outcomes. To reducethese adverse events, the optimal valve would seal and anchor adequatelywithout the need for excessive radial force that could harm nearbyanatomy and physiology.

FIG. 2 is a cross-sectional illustration of prosthetic heart valve 100having leaflets 108 disposed within native valve annulus 250, takenalong line A-A shown in FIG. 1. As seen in FIG. 2, the substantiallycircular annulus section 110 of the stent 102 is disposed within anon-circular native valve annulus 250. At certain locations around theperimeter of heart valve 100, gaps 200 form between the heart valve 100and the native valve annulus 250. Blood flowing through these gaps andaround the valve assembly 105 of prosthetic heart valve 100 can resultin leakage or regurgitation and other inefficiencies which can reducecardiac performance. Such improper fitment may be due to suboptimalnative valve annulus geometry due, for example, to calcification of thenative valve annulus 250 or due to unresected native leaflets.

FIG. 3A illustrates one embodiment of a conformable band 300 that wouldfill irregularities between the heart valve 100 and the native valveannulus 250. As will be described in more detail below, conformable band300 allows for superior sealing between the perimeter of heart valve 100and native valve annulus 250 while affording a low radial outward force.

Conformable band 300 may include a body 310 formed of a ring-likemetallic structure in the shape of a toroid having an inner surface 330defining a central aperture 320 for coupling to heart valve 100 and anouter surface 340 for contacting body tissue. In its relaxed condition,body 310 may have a diameter that is equal to or greater than thediameter of the annulus where it will be implanted. Body 310 ofconformable band 300 may be flexible and capable of contracting in theradial direction when a force is applied thereto to conform to the shapeof the annulus in which it will be implanted.

In one example, body 310 comprises a braided metal fabric that is bothresilient and capable of heat treatment to substantially set a desiredpreset shape. One class of materials which meets these qualifications isshape memory alloys. One example of a shape memory alloy is Nitinol. Itis also understood body 310 may comprise various materials other thanNitinol that have elastic and/or memory properties, such as springstainless steel, trade named alloys such as Elgiloy®, Hastelloy®, CoCrNialloys (e.g., trade name Phynox), MP35N®, CoCrMo alloys, or a mixture ofmetal and polymer fibers. Depending on the individual material selected,strand diameter, number of strands, and pitch may be altered to achievethe desired properties of body 310. Body 310 may be formed, for example,of a braided nitinol mesh and may include a shape-memory material or asuper-elastic material that is capable of collapsing and expanding toconform to patient vasculature. It is also contemplated that the body310 can be constructed from bio-compatible polymer material. In at leastsome examples, body 310 may be hollow and/or loaded with a filler 345 offabric or fibers of various materials that is intertwined and/or locatedwithin the mesh of the conformable band to assist with, sealing,occlusion and healing. For example, conformable band 300 may include afiller 345 of polyester threads or polyester fabric as well as anysuitable implantable fiber material to increase density and/or promotetissue growth. Filler 345 may also include a foam material such as aclosed cell sponge. The density of conformable band 300 may be such thatit impedes the flow of blood through it. In at least some examples,conformable band 300 and/or filler 345 may be formed of a hydrophobicmaterial that expands with moisture. Additionally, conformable band 300and/or filler 345 may be configured from a hydrophobic material thatexpands upon blood contact.

While conformable band 300 is shown in FIG. 3A as a toroid, it will beunderstood that varying shapes and/or sizes may be used to constructconformable band 300. For example, though body 310 has been described asring-like, it will be understood that the perimeter of body 310 maylikewise form an oval, a square or any other desirable polygon. Thecross-sectional shape around the band 300 may also be varied in suchshapes as a circular, oval, polygon, square, diamond, triangle, etc. Forexample, FIG. 3B illustrates a conformable band 300B constructed of abody 310B having a cross-sectional shape of a triangle revolved about acentral axis to form a three-dimensional shape. Moreover, thecross-sectional height and/or width of certain portions of body 310 maybe non-uniform in its relaxed condition as shown in FIG. 3C, whereconformable band 300C includes a body 310C having portion “A” with asmaller cross-sectional height and width than portion “B.” Additionally,conformable band 300 may be discontinuous about a perimeter. Thus, theterm “band” does not limit the contemplated embodiments to constructionsthat are continuous about a perimeter.

FIG. 4 illustrates a conformable band 300 according to a firstembodiment of the present invention disposed about the outer perimeterof heart valve 100. Conformable band 300 may be sewn, glued, welded, orotherwise coupled in any suitable manner to selected struts of stent102. Alternatively, conformable band 300 may be coupled to the outsidesurface of cuff 106. In at least some examples, and as shown in FIG. 4,conformable band 300 may be coupled at the longitudinal level of thevalve leaflets 108.

FIG. 5A illustrates a configuration in which the conformable band 300 isin its relaxed state where the body 310 has fully radially expanded. Themesh of conformable band 300 may be capable of promoting tissue growthbetween the heart valve 100 and the native valve annulus 250. In atleast some examples, conformable band 300 may be treated with abiological or chemical agent to promote tissue growth on the conformableband, further sealing the heart valve within the native valve annulus.

FIG. 5B is a cross-sectional illustration of prosthetic heart valve 100having a conformable band 300 disposed within native valve annulus 250,taken along line B-B shown in FIG. 4. As seen in FIG. 5B, the annulussection 110 of the stent 102 is substantially circular and disposedwithin a non-circular native valve annulus 250. Conformable band 300 hascontracted in certain regions to a radius less than the relaxed stateradius and conformed to fill the gaps that were previously disposedbetween the outer surface of heart valve 100 and the native valveannulus 250. By way of illustration, at region R1 body 310 hascontracted partially and at region R2 body 310 has almost fullycontracted against the wall of prosthetic heart valve 100. With body 310contracting to different amounts around the circumference, conformableband 300 is capable of sealing the irregular-sized gaps formed betweenheart valve 100 and native valve annulus 250.

FIGS. 6 and 7 illustrate two further embodiments of the conformable band300 with a heart valve 100. FIG. 6 illustrates a first variation whereinstead of being separately formed and disposed over stent 102 as inFIG. 4, conformable band 300D may be incorporated into stent 102. Forexample, heart valve 600 may include stent 102D having flared portion601 capable of receiving conformable band 300D. Flared portion 601 maybe annular and bulbous-shaped as shown in FIG. 6. Conformable band 300Dmay be coupled to selected struts 602 of stent 102D such thatsimultaneous delivery of stent 102D and conformable band 300D ispossible.

FIG. 7A illustrates a second variation of a prosthetic heart valvehaving two conformable bands 300, 300′ arranged exteriorly in differentlongitudinal positions near the annulus section 140 of heart valve 100.It will be understood that any number of conformable bands may be usedin conjunction with the contemplated device. Moreover, multipleconformable bands 300 may be incorporated interiorly into the stent asdiscussed above with reference to FIG. 6.

FIG. 7B is a schematic illustration of another embodiment in whichconformable band 300F is configured as a beaded chain. As seen in FIG.7B, a plurality of beads 352 are connected to one another via junctions354 to form a ring. Each bead 352 may be formed of any of the materialsdescribed above with reference to body 310 of FIG. 3A such as, forexample, a nitinol mesh. Additionally, each bead 352 may be packed witha filler (not shown) as described above. Beads 352 may include alongitudinal cross-section that is lens or eye-shaped as shown in FIG.7B, or oval, circular or any other suitable shape. Additionally, eachbead may be generally round or may be dome-shaped having a substantiallyflat surface that contacts a valve assembly or cuff.

FIG. 7C is a photograph of conformable band 300F of FIG. 7B coupled toheart valve 100. For the sake of clarity, the valve assembly, includingthe cuff and leaflets, of heart valve 100 is not attached to stent 102.As seen in FIG. 7C, conformable band 300F is disposed over annulussection 140 of heart valve 100. A second conformable band 300F isdisposed near annulus section 140, adjacent first conformable band 300Fbut closer to transition section 141. Focusing now on conformable band300F, each bead 352 may be shaped to have a width that is substantiallyequal to the width of cell 112 in annulus section 140 and a length equalto about half of cell 112. Beads 352 may be connected to one another andspaced such that each bead 352 is positioned in the center of a givencell 112 around the perimeter of annulus section 140. Additionally,conformable band 300F may be configured such that at a givenlongitudinal position, a single bead 352 is disposed at each cell 112.Conformable band 300F is configured and positioned similar toconformable band 300F, although it will be noted that the two bands300F, 300F are horizontally offset from one another due to the layout ofcells 112 (e.g., the centers of beads 352 of conformable band 300F lineup with junctions 354 of conformable band 300F).

FIGS. 8A-D illustrate the use of conformable band 300 and in a processof sealing a heart valve 100 within a native valve annulus 250. As aninitial step, heart valve 100 having conformable band 300 may bedisposed within a delivery catheter 400 (FIG. 8A) in a collapsedcondition. Delivery catheter 400 may include an outer sheath 410 and aninner shaft 420, the outer sheath 410 being slidable relative to theinner shaft 420. An accepting member 430 may be affixed to inner end ofinner shaft 420 and may include receiving elements (not shown) foraccepting biased retaining elements 118 of the heart valve. Heart valve100 may be coupled to inner shaft 420 at accepting member 430 viaretaining elements 118. The catheter 400 may then be inserted into thepatient, the heart valve 100 and conformable band 300 being in thecollapsed condition, and advanced to the desired site for valvereplacement. For example, for transfemoral insertion, heart valve 100may be inserted into the patient's femoral artery and advancedintravascularly to the descending aorta and the site of the nativeaortic valve. If the heart valve 100 or catheter 400 includes echogenicmaterials, such materials may be used to guide the catheter to theappropriate position using the assistance of three-dimensionalechocaradiography to visualize the heart valve 100 within the patient.

Once heart valve 100 has reached the desired site of deployment, outersheath 410 may be retracted toward the distal end of catheter 400 in thedirection of arrow S to expose heart valve 100 (FIG. 8B). Heart valve100 remains coupled to inner shaft 420 and begins to expand withinnative valve annulus 250 as outer sheath 410 is retracted. FIG. 8Billustrates an intermediate position where heart valve 100 is expandingwithin native valve annulus 250.

As outer sheath 410 is further retracted, more of heart valve 100 isexposed and heart valve expands further into the native valve annulus250. As seen in FIG. 8C, conformable band 300 has contacted the walls ofnative valve annulus 250, and begins to fill any gaps 200 between heartvalve 100 and native valve annulus 250.

Retaining elements 118 may be disconnected by being moved radiallyoutward from receiving elements of accepting member 430 to free theheart valve 100 from catheter 400. FIG. 8D illustrates heart valve 100in its fully expanded state with conformable band 300 fully filling thegaps 200 between fully-expanded heart valve 100 and native valve annulus250. Catheter 400 may then be retracted in the direction of arrow S andremoved from the patient. As discussed above, conformable band 300 maypromote tissue growth along and on the conformable band to seal theheart valve within the native valve annulus. Alternatively, conformableband 300 may be sufficiently dense (e.g. through the use of polyesterfibers or polyester fabric) to adequately seal the heart valve withoutthe need for major tissue growth about the conformable band. Whenconformable band 300 is functioning properly, the heart valve will beadequately sealed so that blood will flow through the interior of heartvalve through valve assembly 105 only and not through any gaps formedbetween the heart valve and the native valve annulus.

It will also be noted that while the inventions herein are predominatelydescribed in connection with the replacement of a tricuspid valve, theinventions are equally applicable to the replacement of other valves,including a bicuspid valve, such as the mitral valve. Moreover, thestent could have different shapes, such as a flared or conical annulussection, a less-bulbous aortic section, and the like, and a differentlyshaped transition section. Additionally, though the conformable band hasbeen described in connection with expandable transcatheter aortic valvereplacement, it may also be used in connection with surgical valves,sutureless valves and other device where sealing is between theperiphery and body tissue. Though a transfemoral approach has beendescribed, it will be understood that a transapical or any othersuitable approach for implanting the heart valve may be used.

Moreover, although the invention herein has been described withreference to particular embodiments, it is to be understood that theseembodiments are merely illustrative of the principles and applicationsof the present invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

It will be appreciated that the various dependent claims and thefeatures set forth therein can be combined in different ways thanpresented in the initial claims. It will also be appreciated that thefeatures described in connection with individual embodiments may beshared with others of the described embodiments.

In some embodiments, a prosthetic heart valve includes a collapsible andexpandable stent having a proximal end and a distal end, a cuff coupledto the stent, a valve assembly including a plurality of leaflets coupledto at least one of the stent or the cuff and a conformable band havingan inner surface disposed near the perimeter of the stent adjacent theplurality of leaflets and an outer surface adapted for contacting bodytissue, the conformable band being configured to seal the valve assemblyagainst leakage by filling gaps between the prosthetic heart valve andthe body tissue.

In some examples, the conformable band may include at least one of ametallic mesh, a braided nitinol mesh or a shape-memory material. Theconformable band may be constructed in the shape of a toroid. Theconformable band may further include polyester fiber intertwined withthe metal mesh to increase density of the conformable band. Theconformable band may further include a polyester fabric intertwined withthe metal mesh to increase density of the conformable band. The stentmay include a plurality of struts and the conformable band is coupled toat least one of the plurality of the struts of the stent.

In some examples, the conformable band may be coupled to an innersurface of the stent. The cuff may have a lumenal surface and anablumenal surface and the conformable band may be coupled to theablumenal surface of the cuff. The conformable band may have anon-circular cross-section. The conformable band may have varyingheights along the perimeter. The conformable band may include abiological agent for promoting tissue growth. The conformable band mayinclude a chemical agent for promoting tissue growth. The conformableband may be continuously formed about the perimeter of the stent. Theconformable band may include at least two rings formed about the stent.

In some embodiments, a method of sealing a prosthetic heart valve in apatient includes positioning the prosthetic heart valve within bodytissue, the prosthetic heart valve comprising (i) a collapsible andexpandable stent, (ii) a valve assembly including a plurality ofleaflets coupled to the stent and (iii) a conformable band having aninner surface disposed about the plurality of leaflets and an outersurface adapted for contacting body tissue, and expanding the stentuntil the conformable band is in sealing contact with the body tissue.

In some embodiments, a prosthetic heart valve includes a collapsible andexpandable stent having a proximal end and a distal end, a valveassembly including a plurality of leaflets coupled to the stent, and aconformable band disposed about the stent between the proximal anddistal ends thereof, the band adapted for creating a fluid seal aboutthe circumference of the stent with an adjacent body tissue. In someexamples, the conformable band may be attached about an outer surface ofthe stent.

In some examples, the conformable band may be attached about an innersurface of the stent. The conformable band may be disposed adjacent theplurality of leaflets. The conformable band may include at least tworings formed about the stent. The band may include an inner surfacedisposed concentric with a perimeter of the stent.

1. A method of sealing a prosthetic heart valve in a patient,comprising: positioning the prosthetic heart valve within body tissue,the prosthetic heart valve comprising (i) a collapsible and expandablestent (ii) a valve assembly including a and (iii) a first conformableband including a plurality of discrete beads extending around acircumference of the stent; and expanding the stent until the pluralityof discrete beads are in sealing contact with the body tissue.